Personal care products have been designed to improve the condition of skin or hair. Unfortunately, however, some benefits, for example scalp strengthening of such products may not be immediately perceived by a user and in fact may take many hours or even days of repeat application to yield consumer-perceivable benefits.
WO 2012/020043 A1 (Unilever) discloses an apparatus for analyzing the condition of skin, scalp or hair of a user, comprising a transducer device responsive to a property of the skin, scalp or hair providing an analog output related to the property, a serial device for outputting a digital signal from an audio signal input, wherein the audio signal is generated from the transducer analog output related to the property, and wherein the serial device provides data packet transmission sufficient for an application to find both a point at which a new packet begins and an opportunity to interpret its received raw data signal.
However, the instrumental measurements to evaluate the condition of scalp may be complicated and/or involve expensive laboratory equipment. Furthermore such measurements often result in numerical parameters that are difficult for laymen to understand or at least relate to the expected product efficacy.
The present inventors have thus identified a need to provide methods which can demonstrate the ability of strengthening scalp and/or preventing dandruff but which does not need specialist equipment and/or is easily related to consumer benefits.